unfavorite

• unfavourite (Commonwealth)
• unfave, unfav (informal)

un- +‎ favorite

unfavorite (comparative more unfavorite, superlative most unfavorite)

1. (informal) Not preferred; in particular, especially disliked.

• unfavored

unfavorite (plural unfavorites)

1. (informal) Something that is not a favorite; particularly something that is especially disliked.

Both the adjective and noun form are rather casual, indeed jocular, and most often used in explicit contrast to favorite, as in “These are some of my favorite and (most) unfavorite things.”

unfavorite (third-person singular simple present unfavorites, present participle unfavoriting, simple past and past participle unfavorited)

1. (Internet) To remove from one’s list of favorites.

Most often used in reference to Twitter, as in “How do I unfavorite a tweet?”

• (all senses): favorite